1. Field of the Invention
The present invention relates to a multilayer piezoelectric element.
2. Description of Related Art
Multilayer piezoelectric elements are used as drivers such as fuel injectors of internal combustion engines for their ability to perform minute displacement. Conventionally, multilayer piezoelectric element 501 of which the cross section view is shown in FIG. 9 has been known. Multilayer piezoelectric element 501 is formed by laminating first internal electrodes 505 and second internal electrodes 507 alternately and disposing piezoelectric layer 503 between first internal electrode 505 and second internal electrode 507. In multilayer piezoelectric element 501, first internal electrodes 505 are connected to each other and second internal electrodes 507 are connected to each other via through holes respectively, and each internal electrode is positioned so as not to be exposed on side face 517 in order to prevent migration from occurring through side face 517.
First internal electrodes 505 are connected to each other via through hole 509 which penetrates piezoelectric layer 503 in the laminated direction so that first internal electrodes 505 are electrically connected to terminal 513. Second internal electrodes 507 are connected to each other via through hole 511 so that second internal electrodes 507 are electrically connected to terminal 515. First and second internal electrodes 505, 507 are disposed so that their periphery portions are positioned inside side face 517 (For example, see Japanese Laid-Open Patent Application No. 2000-261055).